TRICHODERMA IN RICE FIELD SOILS AND THEIR EFFECT ON RHIZOCTONIA-SOLANI

Trichoderma species are present in Bangladesh rice field soils. Their population was the highest in medium land (664 cfu/g) and the lowest i n lowland (270 cfu/g). It was also the highest in Khulna soils (1253 c fu/g) and the lowest in Chittagong soils (99 cfu/k). Four species of T richoderma namely, T. hamatum, T. harzianum, T. koningii and Trichoder ma sp. were identified. Among them T. harzianum was most prevalent. Tr ichoderma speices showed some degree of antagonism against R. solani i n vitro. The cellulolysis adequacy index (CAI) and straw decomposition rate (SDR) of Trichoderma species were higher than R. isolani. T. har zianum showed the highest cellulolysis adequacy index (CAI) and straw decomposition rate (SDR) and appeard to have potentiality for biocontr ol of R. solani.